The proliferation of data communications throughout recent years has caused great demand for high bandwidth reliable data networks. Furthermore, many cost advantages are to be made in deploying wireless data networks, as there is then no need for the great expense of laying cables, wiring buildings, etc., and a more flexible network service may be provided. There is however a single major disadvantage of using a wireless data network instead of a wired network in that the wireless channels over which the data are transmitted can be prone to radio interference from a variety of sources. In order therefore to provide for reliable data communications some mechanism must be provided which allows the network to survive the presence of an interfering signal.